esterly: eucalanus. 



55 



Explanation of Plates. 



All the figures were drawn With the aid of a camera lucida. In general, 

 dark tones are to be interpreted as meaning that the structures so represented 

 are at a higher focus in the preparation than those shown in a lighter tint. 

 This is particularly true of the "interior bodies" and nuclei; simple lines need 

 not necessarily be so looked upon. AH figures are of Eucalanus elongatus. 

 Dana. 



ABBREVIATIONS. 



